Electro-optical (EO) imaging systems used for monitoring a wide field-of-regard (FOR) typically include mechanical components for moving the EO system, such as stepper motors for moving the camera. In order to search over a wide FOR, the EO system must generally either be gimbaled or have its field-of-view (FOV) otherwise movable.
Conventional beam-steering arrangements for missiles include an infrared (IR) transmissive dome at the tip of the missile and an EO system behind the dome, and a gimbal that rotates the entire EO system. The dome is typically rotationally symmetric, placed at the tip of the missile, is spherical or conformal in shape, and is selected with aerodynamic performance as the primary design consideration.
A disadvantage of conventional gimbaled EO systems for certain applications is the need for ample amounts of sway space in order to provide the mechanical movement needed to sweep through the FOR, which can impose expensive packaging constraints on other missile attributes. Other disadvantages of conventional gimbaled EO system arrangements can include significant added weight, cost as well as variable system performance.
In some applications, it is not practical to physically move the EO system. For those instances, it would be desirable for the EO system to provide both pan and tilt functionality for the full FOR without requiring any physical movement of any part of the EO system.